Coupling apparatus including release preventing structure

Abstract

A coupling apparatus includes a pair of cylindrical coupling main bodies which are concentrically and oppositely arranged to each other and which have the same structure as to each other, liners which are accommodated in the coupling main bodies respectively, and a release preventing structure which can selectively resist a rotational force applied to the coupling main bodies coupled with each other, so that a coupling of the coupling main bodies is maintained.

1. A coupling apparatus including a release preventing structure, comprising:
 a pair of cylindrical coupling main bodies which are concentrically and oppositely arranged to each other and have the same structure as to each other; and liners respectively accommodated in the coupling main bodies, 
 wherein each of the coupling main bodies includes a plurality of projecting portions which extend along a longitudinal center line of each coupling main body from a plurality of positions separated from each other at predetermined intervals on a concentric circle having the same diameter on each of opposing surfaces of the coupling main bodies, 
 an engagement piece is provided at a projecting end portion of each of the projecting portions on a side surface facing in one circumferential direction of each of the coupling main bodies in each of the projecting portions, the engagement piece having an engagement surface facing in a direction opposite to the protruding direction of the projecting portion, 
 the pair of coupling main bodies are approached to each other in a state that the coupling main bodies are concentrically opposed to each other, 
 the projecting portions of one coupling main body are inserted into a plurality of indents between the projecting portions of the other coupling main body, and further the coupling main bodies are rotated relative to each other so that engagement surfaces of the projecting portions of the one coupling main body face the engagement surfaces of the projecting portions of the other coupling main body to engage the engagement surfaces of the projecting portions of the one coupling main body with the engagement surfaces of the projecting portions of the other coupling main body in a direction along which the pair of coupling main bodies are separated from each other, 
 the liner in the one coupling main body, is fixed to a fixing member on a side of the liner opposing to the other coupling main body, and the one coupling main body is linearly movable along the longitudinal center line of the one coupling main body with respect to the liner corresponding thereto by a rotation of the one coupling main body on the corresponding liner, 
 the liner in the other coupling main body is fixed to the other coupling main body to be rotational with the other coupling main body and is coupled with a member which is to be coupled with the fixing member, on a side of the liner opposing to the one coupling main body, 
 a rotation assist member is attached on an outer periphery of the one coupling main body to assist the rotation of the one coupling main body relative to the other coupling main body, and 
 after the engagement surfaces of the projecting portions of the one coupling main body are engaged with the engagement surfaces of the projecting portions of the other coupling main body in the direction in which the pair of coupling main bodies are separated from each other, a rotational force is applied to the one coupling main body through the rotation assist member so that the one coupling main body together with the other coupling main body is moved on the liner corresponding thereto to approach to the fixing member along the longitudinal center line and a contact pressure of an end surface of the liner corresponding to the other coupling main body to an end surface of the liner corresponding to the one coupling main body is increased.